According to recent studies, each person has 100 new mutations in their DNA. Almost 70 years ago the father of modern genetics J.B.S. Haldane speculated that this might be so.
Haldane Pioneered Population Genetics
Jack Haldane, along with Ronald Fisher and Sewall Wright founded the study of population genetics; this is the science of how such things as genetic mutations, natural selection, and genetic drift bring about evolutionary change.
In 1935, Haldane studied a group of men in London with hemophilia. Through this research he came to the conclusion that each human had about 150 genetic mutations.
Sequencing Technology Confirms Haldane’s Estimate
Now an international group of 16 scientists says Haldane was right. One of the scientists is Dr. Yali Xue from the Wellcome Trust Sanger Institute in Cambridgeshire, England. A news release from that organization (August 27, 2009) points out that through the work of Xue and colleagues, “Remarkably, the new research, published today in Current Biology, shows that these early estimates were spot on – in total, we all carry 100 – 200 new mutations in our DNA. This is equivalent to one mutation in each 15 to 30 million nucleotides.”
Most of these mutations are quite harmless and cause no ill effects to people’s health or physical appearance.
Chromosomes of Chinese Men Studied
Writing for BBC News (September 2, 2009) Sudeep Chand reports that the scientists “looked at thousands of genes in the Y chromosomes of two Chinese men. They knew the men were distantly related, having shared a common ancestor who was born in 1805.”
Picking up the story the Sanger Institute says, “To establish the rate of mutation, the team examined an area of the Y chromosome. The Y chromosome is unique in that, apart from rare mutations, it is passed unchanged from father to son; so mutations accumulate slowly over the generations.”
After many generations, the researchers found there were only a dozen variations, and that only four were “true mutations that had occurred naturally through the generations.”
Medical Research Aided by Understanding Genetic Mutations
The BBC notes that “It is hoped that the findings may lead to new ways to reduce mutations and provide insights into human evolution.”
Science Daily reports (September 1, 2009) that “Understanding mutation rates is key to many aspects of human evolution and medical research: mutation is the ultimate source of all our genetic variation and provides a molecular clock for measuring evolutionary timescales. Mutations can also lead directly to diseases like cancer.”
Understanding the rate at which mutations occur could lead to ways in which the negative effects of such occurrences might be reduced.
The BBC quotes Joseph Nadeau, from the Case Western Reserve University in the United States as saying, “We are finally obtaining good reliable estimates of genetic features that are urgently needed to understand who we are genetically.”
 |
